A level Biology: Post your doubts here!

[qwertypoiu]

but what if it was stopwatch? :s

Yeah of course stopwatch...
But we cannot have so many significant figures..
Because our finger pressing stop button is not very precise...
54.85 seconds seems to imply you're certain to this many decimal places, but everytime you take a reading it won't be exactly the same.

 

[Studydayandnight]

Can anyone please explain this??

Correct answer is D.

 

[mr dam bhai]

 

[Studydayandnight]

Also, this question, please! Question 28.

Correct answer is C.

 

[princess Anu]

Yeah of course stopwatch...
But we cannot have so many significant figures..
Because our finger pressing stop button is not very precise...
54.85 seconds seems to imply you're certain to this many decimal places, but everytime you take a reading it won't be exactly the same.

do you mean if the student had used a stopwatch then D could have been the ans?

 

[Heba A.Moety]

do error bars extend 2 standard errors above and 2 standard errors below the mean value or only one above and 1 below?!

 

[Heba A.Moety]

Can anyone please explain this??

Correct answer is D.

because lysosomes mainly contain hydrolytic enzymes so the enzyme activity in lysosomes is higher than other organelles

 

[Abdul Hanan]

Also, this question, please! Question 28.

Correct answer is C.

see working on the image.

 

[Heba A.Moety]

a friend's notes for paper 5 hope they help!

 

[lara dalal]

Why is the answer D? How can secondary structure have ionic bonding. Doesnt it have hydrogen only

 

[Studydayandnight]

How do we solve this?

Correct answer is B.

 

[Abdul Hanan]

How do we solve this?

Correct answer is B.

on image.

 

[qwertypoiu]

do you mean if the student had used a stopwatch then D could have been the ans?

No not at all!
Rather my previous message meant even if he used the stopwatch he cannot do decimal places. Simply because repeating the experiment usually gives different decimals each time. Even for measuring fixed times like oscillations in physics, our values are always inaccurate on stopwatches because our reaction times are poor.

 

[Abdul Hanan]

The answer is 75...

it simple... answer is 80.
1.5 seconds -- 2 heart beats
60 seconds -- x
x=(60x2)/1.5
x=80

 

[Maayee]

can someone pls explain why the answer is A for question number 1 in oct/nov 2008 paper 1http://onlineexamhelp.com/wp-content/uploads/2012/05/9700_w08_qp_1.pdf

 

[princess Anu]

32 help!!

 

[saturn21]

Hmmm are you sure?
Please check again I really think answer should be C

I remember solving this question...and the answer was 80 (C)

 

[hizirofaki]

View attachment 53252
hope this make things clear

thx ur amazing

 

[Abdul Hanan]

can someone pls explain why the answer is A for question number 1 in oct/nov 2008 paper 1http://onlineexamhelp.com/wp-content/uploads/2012/05/9700_w08_qp_1.pdf

greatest number of cells in field of view means least magnification (most cells visible). so its simply the one with least total magnification that is x5 and x10 in this case.

 

[Maayee]

greatest number of cells in field of view means least magnification (most cells visible). so its simply the one with least total magnification that is x5 and x10 in this case.

ok thankkk uuu